Grinding apparatus for side surface of a workpiece

ABSTRACT

A grinding apparatus used for feeding a grinding wheel toward the side surface of a workpiece along a spiral pathway. The grinding wheel is rotatably mounted upon a swing arm which is fixedly mounted upon a spindle which is, in turn, operably connected to first and second feeding means. The first feeding means may impart rotational and axial movement to the swing arm, while the second feeding means imparts only an axial movement thereto. Several preferable feed pathways of the grinding wheel may be obtained by appropriately combining the movements which may be obtained from the first and second feeding means.

United States Patent 91 Kik'uchi et al.

[ Nov. 19, 1974 GRINDING APPARATUS FOR SIDE SURFACE OF A WORKPIECE [22] Filed: Nov. 3, 1972 [21] Appl. No.: 303,602

[30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS 584,919 1/1947 Great Britain 51/124 L Primary Examiner-A1 Lawrence Smith Assistant Examiner-Robert C. Watson Attorney, Agent, or FirmOblon, Fisher, Spivak, McClelland & Maier [57] ABSTRACT A grinding apparatus used for feeding a grinding wheel toward the side surface of a workpiece along a spiral pathway. The grinding wheel is rotatably mounted upon a swing arm which is fixedly mounted upon a spindle which is, in turn, operably connected to first and second feeding means. The first feeding means may impart rotational and axial movement to the swing arm, while the second feeding means imparts only an axial movement thereto. Several preferable feed pathways of the grinding wheel may be obtained by appropriately combining the movements which may be obtained from the first and second feeding means.

7 Claims, 5 Drawing Figures GRINDING APPARATUS FOR SIDE SURFACE OF A WORKPIECE BACKGROUND OF THE INVENTION I. Field Of The Invention The present invention relates generally to machining devices, and more particularly to an improved grinding apparatus for the side surface of a workpiece 2. Description Of The Prior Art In conventional grinding apparatus, when a grinding wheel is fed toward the side surface of a workpiece for the grinding thereof, it has first been moved in a direction parallel to the side surface thereof and subsequently fed in an axial direction toward the surface. In other words, the grinding wheel has been fed via a pathway having linear components at right angles to each other.

It should therefore be apparent that a relatively longer distance and a greater amount of time is consequently consumed in merely completing the operation whereby the grinding wheel comes into close proximity with the workpiece so that the grinding operation may be subsequently performed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new and an improved grinding apparatus capable of grinding the side surface of a workpiece.

Another object of the present invention is to provide a grinding apparatus in which the grinding wheel may be fed toward the workpiece through a shorter distance in order to subsequently grind the side surface thereof.

Still another object of the present invention is to provide a grinding apparatus in which a grinding wheel may be easily preset in a required angular position relative to the side surface of the workpiece.

A further object of the present invention is to provide a grinding apparatus which will substantially reduce the time employed in effecting a particular cycle of the grinding operation so as to obtain a high degree of efficiency.

The foregoing and other objectives are achieved according to the present invention through the provision of a grinding apparatus for grinding the side surface of a workpiece, wherein, during a grinding cycle, the grinding wheel, which is secured to a spindle by means of a swing arm, is fed toward the .workpiece via an appropriate spiral pathway which is derived by combining the rotational and axial movements of first and second spindle feeding mechanisms. Thereafter, when the grinding operation is accomplished, the grinding wheel is returned to its original position through a similar spiral pathway.

BRIEF DESCRIPTION OF THE DRAWINGS Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in conjunction with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

FIG. 1 is an elevational view, partly in section, of a grinding apparatus constructed according to the present invention;

FIG. 2 is an enlarged cross'sectional view of a position adjusting device for a grinding wheel, taken along the line II-Il in FIG. 1;

FIG. 3 is a cross-sectional view taken along the line IIIIII in FIG. 1;

FIG. 4 is a cross-sectional view taken along the line IV-IV IN FIG. I; and

FIG. 5 illustrates schematically the loci of the grinding wheel during the various feeding operations according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings. and more particulary to FIG. 1 thereof, a bed 1 has a head stock 2 slidably installed thereon while a chucking device 3, within which a workpiece W is clamped. is mounted at one end of a main spindle which is rotatably supported within the head stock 2 and is to be rotated by a drive motor, not shown.

A main body 4 is mounted upon the head stock 2 and is selectively moved by rotational movement of a pinion gear 6 which is engaged with a rack 5 fixedly secured upon the head stock 2. The pinion gear 6 is rotatably mounted within the main body 4 and is driven manually or automatically when the main body 4 is required to be adjustably shifted in accordance with the length of the workpiece W. Fixedly mounted within the main body 4 is a sleeve 7 within Which a rotatably and axially movable spindle 8 is supported by means of a stroke bearing 9.

Similarly, a drive shaft 17 is rotatably supported within the spindle 8 through means of ball bearings, a pulley 14 being fixedly keyed to the right end of the drive shaft 17. Similarly, one end of a swing arm I0 is secured to a flanged portion located at the right end of the spindle 8, while a position adjusting device T, for adjusting the angular position of a cup-shaped grinding wheel 13, is provided upon the other end of the swing arm 10.

The position adjusting device T for the grinding wheel 13 will now be described in detail with reference to FIG. 2. An adjustable sleeve 11 is tiltably mounted within the swing arm 10 and is prevented from rotational movement relatively thereto by means of a detent screw 62 which is secured within the swing arm 10, the end of which projects within a detent positioned within sleeve 11. The adjustable sleeve 11 is supported by means of a spherical bearing 63 which is interposed between the sleeve 11 and the swing arm 10, while rotatably supported, by ball bearings, within the sleeve 1 I is a rotary shaft I2 upon one end of which the cupshaped grinding wheel 13 is fixedly fastened by means of a clamping flange 61. A pulley 15 is fixedly mounted upon the other end of the rotary shaft 12 and is driven by means of a belt 16 which connects the pulleys l4 and 15.

The center of spherical curvature G of the spherical bearing 63 is located upon the axis of the shaft 12 so that the cup-shaped grinding wheel 13 may be properly tilted by means of the adjustable sleeve 11 so as to be brought into a desired angular position. A flanged member 65 is secured near the end of the adjustable sleeve 11 by means of a lock nut 66 which is thrcadably engaged with sleeve 11, a plurality of adjusting screws 64, which are provided upon the flanged member 65, being circumferentially, equally spaced relative to one another so that the adjustable sleeve 11 may be angularly tilted about the center G by turning the adjusting screws 64 before a grinding operation. Thus, the grinding surface of the grinding wheel 13 is adjusted to an angular position perpendicular to the axis of the main spindle so that the grinding surface can be corresponded to the side surface of the workpiece W. Such adjustments are small, but the belt 16 nevertheless may be of a flexible material to permit proper contact thereof with the pulley even when it is slightly tilted. A cover case 54 which is provided for guarding the rotary transmission device including the pulleys 14 and 15, and the belt 16, is secured to the swing arm 10 by bolt means. 7

Referring again to FIG. 1, a spline 18 which is formed upon the outer periphery of the drive shaft 17 at the left end thereof is operatively connected through a spline sleeve 22 to a spline 21 which is formed upon the right end of a rotating shaft which is driven by the drive motor 19. Similarly, a feed screw 23 and a spline 24 are co-axially disposed upon the left end portion of spindle 8, and engageably mated with the spline 24 is a pinion gear 25 with which a rack piston 26 is operatively meshed. A threaded member 27, which is rotatably supported upon the main body 4 through means of ball bearings but which is also refrained from axial movement relative thereto, is coaxially disposed and threadably engaged with the feed screw 23 so that the spindle 8 may be axially moved when the threaded member 27 is rotated. In addition, there is drivingly connected to the threaded member 27, by means of a key 29, a worm wheel 28 which is, in turn, meshed with a worm rack 30.

As shown in FIG. 3, the rack piston 26 is slidably mounted within cylinders 31a and 31b. Movably received within the rack piston 26 is an axial cushion adjusting shaft 34 at one end of which an adjusting knob 33 is provided for adjusting the position of shaft 34 so as to change the feed rate of the rack piston 26. Radial ports 35 and 37, which are communicated with each other through means of an axial bore 36 within the cushion adjusting shaft 34, are provided for connecting the annular chamber, defined between shaft 34 and cylinder 31b, to a radial port 39 within a cover member 32 which is secured to the right end of cylinder 31b. A stroke adjusting sleeve 32a, for defining the stroke of the rack piston 26, is threadably mounted within cover member 32 and is threadably mounted upon the cushion adjusting shaft 34, the members 32, 32a, and 34 all being co-axially disposed. Sleeve 32a extends outwardly from the cylinder 31b and cover member 32, and has a knob 32b integrally formed upon the projecting end thereof for accomplishing the adjustment of sleeve 32a.

A radial port is likewise provided for supplying or exhausting the pressurized fluid into or from the annular chamber defined by shaft 34 and cylinder 31a. Ports 38 and 39 are similarly provided for supplying or exhausting fluid under pressure into or from the annular chamber of the cylinder 31b. These ports 38, 39 and 40 are connected to a solenoid valve 43 through appropriate hydraulic circuitry. A variable throttle valve 41, and a check valve 42, which are connected in parallel with each other are arranged between the port 38 and the solenoid valve 43 so as to restrain the flow of fluid and attain a cushioning effect as will be described hereinafter.

As shown in FIG. 4, both ends of the worm rack 30 are respectively slidably received within cylinders 44a and 44b. Fixedly atached to the end face of the cylinder 44a, in co-axial alignment therewith, is a plug member 57 upon which a positioning ring 56 is provided with a set screw for restricting the axial position of a longitudinal abutment member 58. The abutment member 58 is threadably engaged within the plug member 57 and is axially movable by rotation of an adjusting ring 55 which is fixed upon the abutment member 58 so as to control the stroke of the worm rack 30. A reciprocating bar 59, which is threadedly fixed to the left end of worm rack 30, is slidably received within the abutment member 58, and is provided with a dog on one end thereof, which dog cooperates with a limit switch, not shown, for assuring the stroke of the worm rack 30.-

Radial ports 45 and 46, respectively provided within the cylinders 44a and 44b in order to supply or exhaust fluid under pressure into or out of the chambers thereof, are connected to a solenoid valve 5] through appropriate hydraulic circuitry. A variable throttle valve 52 and a check valve 53, which are connected in parallel with each other, are provided between the port 46 and the solenoid valve 51 for regulating the flow of fluid discharged from the cylinder 44b.

A handle shaft 47, rotatably mounted within the main body 4, is provided with a spline 48 at the left end thereof which is engageable with the worm rack 30. A co-axial clutch member 50 is rotatably mounted upon the handle shaft 47 and is operatively connected with a rack piston of a compensation feed device. not shown, which is provided for compensating for the wear of the grinding wheel 13. A manual operating handle 49, which is keyed upon the handle shaft 47 so as to be only axially movable relative thereto, is operably connected to the clutch member 50 by means of a knob 69 which rotates therewith.

The operation of the grinding apparatus for the side surface of a workpiece constructed according to the present invention will now be described with reference to those views depicting the feeding movement of the cup-shaped grinding wheel 13. The cup-shaped grinding wheel 13 is initially rotated by means ofa pulley 15, the belt 16, and the pulley 14 which is driven by means of the drive motor 19 acting through the rotating shaft 20, the splined sleeve 22 and the driven shaft 17. Generally speaking two kinds of feeding methods are available according to the illustrative apparatus to feed the cup-shaped grinding wheel 13 toward the side surface of the workpiece W which is clamped within the chuck ing device 3. That is, one feeding method is performed by merely operating the rack piston 26, while the other feeding method is effected by co-operating the movements of the rack piston 26 with that of the worm rack 30.

With respect to the first method, the solenoid valve 43 is changed over so as to supply the fluid under pressure intov the cylinder 31a by means of the port 40, whereby the rack piston 26 is moved toward the right as seen in FIG. 3, thereby rotating the pinion gear 25.

in a clockwise direction. Consequently, the spindle 8 is rotated in a clockwise direction in FIG. 3, by engagement with the pinion gear 25 by means of splined portion 24, whereupon the swing arm 10 is pivotably moved around the axis of spindle 8. At the same time, the spindle 8 is axially moved toward the left, as viewed in FIG. 1, since the feed screw 23 thereon is in engagement with the threaded member 27 which is prevented from rotating at this time.

Consequently, the resulting path of travel of the cupshaped grinding wheel 13, as it is being fed toward the side surface of the work-piece from its original starting position, is drawn in such a manner of a linearly oblique pathway a, as shown in FIG. 5A, although the entire path over which the wheel actually travels is that of a spiral. The grinding wheel 13 is rapidly moved as fluid within the cylinder 31b is returned to a reservior through the axial bore 36 and the radial ports 37 and 39. Thereafter, the grinding wheel is slowly fed or accurately moved to the side surface of the workpiece W, because the rack piston 26 covers the port 35, whereby exhaust fluid within the cylinder 31b flows only through the port 38 and the variable throttle valve 41 into the reservoir, and thus, a cushioning effect is obtained upon the rack piston 26. The side surface of the workpiece W is subsequently ground in accordance with the stroke of the grinding wheel which is defined by the cushion adjusting member 32b.

After the grinding operation is completed, the solenoid valve 43 is changed over so that the rack piston 26 is now slidably moved toward the left as viewed in FIG. 3. As a result, the splindle 8 is axially and rotationally moved by the reverse rotational motion of the pinion gear 25, and consequently, the grinding wheel is restored to its original position through .a resulting linear oblique pathway a, as shown in FIG. 5A.

With respect to the second method, the stroke of the worm rack 30 is initially adjusted and controlled by changing the position of the abutment member58 with the aid of the adjusting ring 55 so as to regulate the leftward movement of rack 30, as viewed in FIG. 4. Subsequently, the two solenoid valves 43 and 51 are simultaneously changed over, so as to thereby cause the rack piston 26 and the worm rack 30 to move toward the right and left, respectively, as seen in FIGS. 3 and 4 respectively. The pinion gear 25 is therefore rotated, as well as the worm wheel 28 along with the threaded member 27. The spindle 8 is thus axially moved toward the left as seen in FIG. 1, by means of the worm wheel 28 and is further axially and rotationally moved by means of the pinion gear 25. Thus, the grinding wheel 13 rapidly approaches the workpiece via a pathway indicated by a+b as shown in FIG. 58. That is, the pathway a+b obviously corresponds to the combination of the spiral pathway induced by the rack piston 26 as well as the axial pathway induced by the worm rack 30. When the grinding wheel 13 is moved into the vicinity of the workpiece W or brought into a position Ll, the

worm rack 30 ceases operation because it engages the abutment member 58. Subsequently, the grinding wheel continues to be fed toward workpiece W at a slower rate by the rack piston 26 through a linearly oblique pathway 0, as seen in FIG. 58, so as to subsequently grind the side surface of the workpiece.

In reverse, the grinding wheel is restored to its original position through a linearly oblique pathway (a-l-b), by simultaneously actuating the rack piston 26 and the worm rack 30 in their respective reverse directions.

It is also possible to feed the cup-shaped grinding wheel 13 toward the workpiece along a path defined by the locus shown in FIG. 5C. In this operation, the solenoid valves 43 and 51 are controlled in a predetermined sequence. Namely, the cup-shped gringing wheel 13 is rapidly moved by the rack piston 26, in an oblique direction with respect to the workpiece until its axis is at the proper parallel position relative to the workpiece axis, whereupon it may then be slowly fed toward the workpiece by means of the worm rack 30, in an axial direction. In accomplishing this operation, only the rack piston 26 is initially operated so as to bring the grinding wheel 13 through a linear oblique pathway a into a position L2, as shown in FIG. 5C, at which time the rotation of the spindle 8 is not effected any longer since the rack piston 26 is now engaged with the stroke adjusting sleeve 32a, which has been adjusted by means of knob 32!). The worm rack 30 is then moved toward the left. as shown in FIG. 4, so as to rotate the threaded member 27 in order that the spindle 8 by axially moved by means of the feed screw 23 thereon. Accordingly, the grinding wheel is fed toward the side surface of the workpiece in the axial direction only.

When the grinding operation is finished and the grinding wheel is required to be restored to its original position, the rack piston 26 is actuated as well as the worm rack 30. The grinding wheel is therefore moved through a linear oblique pathway a+b, as seen in FIG. 5C. As described hereinbefore, the motion of the linear pathway a+b for the grinding wheel is accomplished by combining the spiral motion of the rack piston 26 and the axial motion of the worm rack 30.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is to be understood therefore, that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A grinding apparatus for the side surface of a workpiece comprising:

a bed;

a head stock mounted upon said bed for holding a workpiece thereon;

a main body mounted upon said head stock;

a spindle rotatably and slidably carried within said main body;

a swing arm attached to said spindle at one end thereof;

a grinding wheel rotatably mounted on the other end of said swing arm;

drive means for driving said grinding wheel; and

first feeding means mounted on said main body and operatively connected with said spindle for simultaneously imparting a rotational and axial movement to said swing arm so as to feed the grinding wheel toward the workpiece via a spiral feed pathway.

2. A grinding apparatus as set forth in claim 1, which further comprises a second feeding means mounted on said main body and operably connected to said spindle through said first feeding means for imparting an axial movement to said spindle in co-operation with said first feeding means so as to feed the grinding wheel toward the workpiece via a feed pathway which is determined by combining the movements of said spindle derived from the actuation of both of said first and second feeding means.

3. A grinding apparatus as set forth in claim I, i

wherein said first feeding means comprises;

a first actuating cylinder provided within said main body; v

a rack piston member slidably mounted within said first cylinder and coupled with means drivingly connecting said piston to said spindle for providing axial movement to said spindle;

stroke adjusting means threadably mounted upon said first cylinder for regulating the stroke of said rack piston member; and

feed screw means provided upon said spindle for moving said spindle in an axial and rotational direction by co-operation with said rack piston member.

further comprises adjusting means for appropriately adjusting the angle of the axis of the grinding wheel with respect to the axis of the workpiece. whereby the grinding surface of the grinding wheel is maintained at an angular position being in perpendicular relation to the axis of the workpiece.

6. A grinding appartus as set forth in claim 5, wherein said adjusting means comprises:

an adjustable sleeve tiltably supported upon a spherical bearing within said swing arm at one end thereof;

a rotary shaft rotatably mounted within said ajdustable sleeve upon which said grinding wheel is fastened; and, I

adjusting screw means mounted upon said adjustable sleeve for adjusting said grinding wheel to said angular position by tilting said adjustable sleeve.

7. A grinding apparatus as set forth in claim 6,

wherein said drive means comprises:

a drive motor mounted on said main body;

a drive shaft rotatably mounted within said spindle and drivingly connected with said drive motor for rotation therewith; and.

transmission means for transmitting the rotation of said drive shaft to said rotary shaft for driving said grinding wheel. 

1. A grinding apparatus for the side surface of a workpiece comprising: a bed; a head stock mounted upon said bed for holding a workpiece thereon; a main body mounted upon said head stock; a spindle rotatably and slidably carried within said main body; a swing arm attached to said spindle at one end thereof; a grinding wheel rotatably mounted on the other end of said swing arm; drive means for driving said grinding wheel; and first feeding means mounted on said main body and operatively connected with said spindle for simultaneously imparting a rotational and axial movement to said swing arm so as to feed the grinding wheel toward the workpiece via a spiral feed pathway.
 2. A grinding apparatus as set forth in claim 1, which further comprises a second feeding means mounted on said main body and operably connected to said spindle through said first feeding means for imparting an axial movement to said spindle in co-operation with said first feeding means so as to feed the grinding wheel toward the workpiece via a feed pathway which is determined by combining the movements of said spindle derived from the actuation of both of said first and second feeding means.
 3. A grinding apparatus as set forth in claim 1, wherein said first feeding means comprises; a first actuating cylinder provided within said main body; a rack piston member slidably mounted within said first cylinder and coupled with means drivingly connecting said piston to said spindle for providing axial movement to said spindle; stroke adjusting means threadably mounted upon said first cylinder for regulating the stroke of said rack piston member; and feed screw means provided upon said spindle for moving said spindle in an axial and rotational direction by co-operation with said rack piston member.
 4. A grinding apparatus as set forth in claim 2, wherein said second feeding means comprises: a second actuating cylinder provided within said main body; a worm rack member slidably mounted within said second cylinder; a worm wheel means engageable with said worm rack member and operably connected with a feed screw means which is included in said first feeding means and provided upon said spindle means; and, an abutment member adjustably mounted upon said second cylinder for controlling the stroke of said worm rack member.
 5. A grinding apparatus as set forth in claim 1, which further comprises adjusting means for appropriately adjusting the angle of the axis of the grinding wheel with respect to the axis of the workpiece, whereby the grinding surface of the grinding wheel is maintained at an angular position being in perpendicular relation to the axis of the workpiece.
 6. A grinding appartus as set forth in claim 5, wherein said adjusting means comprises: an adjustable sleeve tiltably supported upon a spherical bearing within said swing arm at one end thereof; a rotary shaft rotatably mounted within said ajdustable sleeve upon which said grinding wheel is fastened; and, adjusting screw means mounted upon said adjustable sleeve for adjusting said grinding wheel to said angular position by tilting said adjustable sleeve.
 7. A grinding apparatus as set forth in claim 6, wherein said drive means comprises: a drive motor mounted on said main body; a drive shaft rotatably mounted within said spindle and drivingly connected with said drive motor for rotation therewith; and, transmission means for transmitting the rotation of said drive shaft to said rotary shaft for driving said grinding wheel. 